Modern mobile devices, such as smart phones, include motion sensors that can be used by a vehicle navigation application to determine the position, speed and heading of a vehicle on which the mobile device is mounted. For navigation applications, the mobile device is often mounted on the dashboard of a vehicle, allowing the user to view turn-by-turn directions provided on a display screen of the mobile device. The user can also be provided with a compass heading on the display screen, allowing the user to determine the direction of travel. To avoid distraction when driving, a driver of the vehicle may rotate the mobile device in their direction to gain a better view of the display screen. Rotating the mounted mobile device, however, can cause errors in compass heading calculations since the sensitive axis of the motion sensor is oriented away from the direction of travel.